1. Field of the Invention
The present invention relates to a film deposition method and a device therefor.
2. Description of Prior Art
In the past, several approaches were suggested as an alternative to the conventional electrochemical plating technology, for the purpose of depositing a thin-film material on a substrate or plating or coating the same with such a thin-film, for example, the vacuum evaporation method and the deposition method utilizing ionization and acceleration of particles. In particular, the latter method has the advantageous characteristics that adhesion is excellent and surface cleaning and film deposition are contigeously carried out. It may be generally classified into two categories; (i), the so-called "system operating in a discharge region" wherein, as the substrate of metal material serving as a negative discharge electrode, a glow discharge is established with the aid of discharge sustaining gas and the proper material to be deposited on the substrate is vapourized and ionized in the discharge region and then accelerated toward the substrate supplied with negative voltage to form a thin-film of desired thickness on the substrate: and (ii), the so-called "system operating in a high vacuum region" wherein ionization is achieved within a discharge chamber and the thus obtained ions are extracted from a small aperture formed in the discharge chamber with the use of an ion extractor electrode supplied with negative voltage and are accelerated toward the high vacuum region with the result that ions having substantially the same flight direction and kinetic energy reach the substrate in the form of a single beam. Nevertheless, while the system (i) has advantages that the structure is simple and deposition rate is considerably high and the film deposition is accomplished on not only one of major surfaces of the substrate confronting a source of material vapour but also the remaining surfaces of the substrate, it is disadvantageous in that substrate temperature is remarkably increased because of the substrate operating as one of the discharge electrodes within the discharge region and the film deposition is of the non-directional and porosity nature because the kinetic energy values of the respective ions are not equal. On the other hand, the system (ii) is found advantageous since no increase in substrate temperature occurs and the substrate is free from the restrictions on material and further ion acceleration is substantially uniform in energy and direction to thereby form fine-quality disposed films of various kinds, however, the structure is complex and the deposition rate is low.